Show arrow datatype when hovering a component (#10007)

Small usability improvement

Author: emilk

Cargo.lock

@@ -6861,6 +6861,7 @@ dependencies = [
  "egui_extras",
  "egui_plot",
  "itertools 0.14.0",
+ "re_arrow_util",
  "re_byte_size",
  "re_capabilities",
  "re_chunk_store",

crates/store/re_sorbet/src/chunk_schema.rs

@@ -1,4 +1,4 @@
-use std::ops::Deref;
+use std::ops::{Deref, DerefMut};
 
 use arrow::datatypes::{Field as ArrowField, Schema as ArrowSchema};
 
@@ -42,6 +42,13 @@ impl Deref for ChunkSchema {
     }
 }
 
+impl DerefMut for ChunkSchema {
+    #[inline]
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.sorbet
+    }
+}
+
 /// ## Builders
 impl ChunkSchema {
     pub fn new(

crates/viewer/re_data_ui/Cargo.toml

@@ -19,6 +19,7 @@ workspace = true
 all-features = true
 
 [dependencies]
+re_arrow_util.workspace = true
 re_byte_size.workspace = true
 re_capabilities = { workspace = true, features = ["egui"] }
 re_chunk_store.workspace = true

crates/viewer/re_data_ui/src/instance_path.rs

@@ -244,6 +244,12 @@ fn component_list_ui(
                     component_descr
                         .component_name
                         .data_ui_recording(ctx, ui, UiLayout::Tooltip);
+                    if let Some(data) = unit.component_batch_raw(component_descr) {
+                        ui.list_item_flat_noninteractive(
+                            re_ui::list_item::PropertyContent::new("Data type")
+                                .value_text(re_arrow_util::format_data_type(data.data_type())),
+                        );
+                    }
                 });
 
                 if interactive {